Existing fuel delivery systems which use an in-tank fuel pressure regulator usually employ an energy absorbing device mounted on or near the fuel rail. The energy absorbing device serves to compensate for fuel pressure pulsations created in the fuel rail that occur as a result of sequential firing of fuel injectors operatively connected to the fuel rail.
A known energy absorbing device is a damper mounted on the fuel rail. A damper of this type is disclosed in commonly-assigned, co-pending U.S. patent application Ser. No. 09/086,084, entitled "Fuel Rail Damper", filed, May 28, 1998, which is incorporated herein in its entirety by reference. This known damper has an upper chamber and a lower chamber separated by a solid, flexible diaphragm. The upper chamber contains a spring biased against the diaphragm. The lower chamber has an opening which allows fuel to enter from the fuel rail and contact the diaphragm. An upper flange of the lower chamber extends inwardly at an angle to form a radial shoulder, which maximizes an effective area of the diaphragm. Under certain operative conditions, the diaphragm can adhere to the radial shoulder, which substantially reduces the effective area of the diaphragm, and can cause the diaphragm to become non-responsive to pressure pulses. Thus, the radial shoulder, which is employed to maximize the effective area of the diaphragm, can, under certain conditions, actually minimize the operability of the damper.